The twenty-third Conference of the Parties (COP-23) of the United Nations Framework Convention on Climate Change (UNFCCC) was held in Bonn on 6-17 November 2017, under the presidency of Fiji. COP-23 focused, in particular, on developing rules to implement the 2015 Paris Agreement and on raising ambition for climate protection. Since this was the first "Oceanic" COP, special attention was given to supporting the countries of the Global South in their efforts to reduce emissions, adapt to climate change, and deal with the unavoidable impacts of climate change. This article summarizes the main developments and results of COP-23.

Last year's conference of the global climate change regime took place from 2 until 15 December 2018 in Katowice, Poland. The conference had two main objectives: operationalising the Paris Agreement by adopting detailed rules for its implementation, and starting the process of strengthening Parties' climate protection contributions. This article covers the negotiations on these two sets of issues and also includes a discussion of other recent climate activities by Parties and non-Party actors. Success of the negotiations in Katowice was far from assured, but in the end COP24 concluded with the adoption of the "Katowice Climate Package" setting out detailed guidelines on how to implement its various elements. However, the conference fell short on the first objective, none of the major emitting countries was ready to step up its climate ambition. The most important aspect of the Katowice outcome is therefore that it has brought the wrangling about implementation procedures to a close, making way for the true task at hand: the strengthening of national and international activities to protect the climate and the implementation of the existing pledges. Arguably, a key factor that has been slowing down climate policy is the power of entrenched interests. The article therefore concludes with a reflection on how such barriers to climate action may be overcome and what role future COPs may play in this regard.

The current global momentum for carbon pricing has lately produced innovative hybrids: carbon taxes allowing the use of offsets from emission sources not targeted by the carbon tax for compliance with the tax load. This study aims at filling the knowledge gap in existing literature by exploring the potential impacts of domestic offset components in carbon taxes on mitigation of national emissions, including the country examples Colombia, Mexico and South Africa.
The findings indicate that the use of offsets in carbon taxes may significantly influence mitigation of national emissions both positively and negatively. On the one hand, this model may result in real emission reductions from offset projects and positive spillover effects of efforts to reduce emissions from emission sources covered by the carbon tax to other emission sources. Furthermore, the offsetting component can be used as a bargaining chip in political negotiations facilitating the introduction of mitigation policies and measures and/or strengthening their ambition level. On the other hand, it also entails serious risks: Offsetting could compromise the environmental integrity of the carbon tax through low-quality offsets. Furthermore, offsets reduce incentives to curb emissions in the emission sources covered by the carbon tax, potentially leading to carbon lock-in effects. Moreover, an offsetting component could provoke opposition to further climate policies and measures for emission sources generating offsets, as replacing the offsetting component with mandatory emission reduction policies would eliminate revenues from offset credits. General opposition of stakeholder groups to the introduction of offsets may even hinder the introduction of carbon pricing instruments and offsetting altogether.
The study identifies options that could be employed to increase potential positive effects of introducing an offset component to a carbon tax and mitigate related risks, pointing to the country examples included, where appropriate.